General Motors' decision to sell Opel to a consortium of Canadian car parts maker Magna and Russia's Sberbank is an important intermediate step but not a final one, Sberbank said on Thursday.

This decision didn't come out easy, neither for General Motors nor for us. Talks were very difficult and the deal's structure is unprecedentedly complicated, Sberbank's chief executive German Gref said in a statement.

The agreement of intention alone is a document of over 1,000 pages. And it is too early to say that a final decision has been taken. This is only a very important, intermediate stage of the deal, Gref added.

(Reporting by Oksana Kobzeva and Dmitry Sergeyev, writing by Dmitry Zhdannikov, Editing by Melissa Akin)